The Premier League and European champions issued a statement this evening describing their "growing irritation" at continuing comments seemingly emerging from the Spanish club concerning their interest in the Portugal attacker.

The statement on the club's website reads: "Manchester United has watched with growing irritation the comments attributed to Real Madrid over their alleged desire to sign Cristiano Ronaldo. "The facts are: the player is on a long-term contract and his registration is held by Manchester United; The player is not for sale.

"The club will have no alternative but to report Real Madrid to the world governing body, FIFA, if it continues to behave in this totally unacceptable fashion. These public attempts to unsettle the player are completely against the regulations and the club will not tolerate them any longer.

"In addition, the club is certain that they are a distraction for the Portuguese national squad as they prepare for the European Championships. No one should be in any doubt that Manchester United will do everything in its power to keep its best players."

Meanwhile, as the annual clamour for top European players begins in earnest following the conclusion of a season that saw United retain their Premier League crown as well as win a third European Cup, Alex Ferguson is looking to make a small number of additions to a squad that is already the envy of most of their rivals.

In echoes of last summer when United spent around £52 million on Owen Hargreaves, Nani and Anderson, Ferguson has been handed a similar budget to address the need for attacking reinforcements and cover at full-back, primarily to find a long-term replacement for club captain Gary Neville.

Neville has made a full recovery from the injury that keep him on the sidelines for over a year, however Ferguson recognises that his aging legs will prevent him from reaching the same consistent levels of form and fitness he achieved in the past during his long Old Trafford career.

The right back position has been filled manfully over the season by Wes Brown and, on occasion, Hargreaves.

Ferguson is a long time admirer of Manchester City's Micah Richards and the ongoing uncertainty over the future of manager Sven Goran Eriksson and any likely successor at Eastlands has convinced the United manager that a bid in the region of £20 million would be accepted.

Were he to be unsuccessful, however, attention would quickly turn to Sevilla's Brazilian defender Daniel Alves.

Alves has been one of the key performers in Sevilla's excellent form over recent seasons, in which they twice won the Uefa Cup and challenged for the Spanish title, as well as winning the domestic cup there.

Alves' team-mate and compatriot Luis Fabiano is seen as the ideal orthodox striker that United wish to add to the squad and the pair could be coaxed away from southern Spain for a combined fee of around £30 million.

Last season the Brazilian striker scored 34 goals from 44 appearances in all competitions for Sevilla and, despite Ferguson's willingness to field teams with a fluid front three rather than relying on a traditional target man, his direct, physical game would add another dimension to United's forward line.

Wishing to avoid disrupting a winning team, United are likely to bring in no more than three new faces over the coming weeks, with at least the same number heading out of Old trafford.

Louis Saha, whose United career has been blighted by injury since his £12.8 million move from Fulham in Jan 2004, will definitely be sold whilst negotiations are at an advanced stage to take Gerard Pique back to Barcelona.

Offers will also be encouraged for Mikael Silvestre, whose first team opportunities have been limited in recent years.